In recent years, from the viewpoint of prevention of global warming and usage restraint of fossil fuels, solar light energy is focused on as natural energy which exhausts a small amount of toxic substances such as carbon dioxide or nitrogen oxide or as a renewable energy resource.
For example, as a facility using the solar light energy, there is a heat collection facility that includes a light collection device having a mirror and a heat receiver that receives light from the mirror.
For example, as the light collection device in the heat collection facility, there is a light collection device disclosed in PTL 1 described below.
The light collection device includes a mirror structure having a plurality of mirrors, and a driving device that coordinates the mirrors of the mirror structure in a target direction. The mirror structure includes the plurality of mirrors, and includes a laminate sheet adhering to a rear surface of each mirror, a truss structure that is disposed on the rear surface side of the laminate sheet, and a spacer piece that is disposed between the laminate sheet and the truss structure and maintains a curved surface of the mirror.
In order to improve weight reduction of the mirror structure, in the mirror structure, a deformable and thin mirror is used, and the mirror is supported so as not to be deformed by the spacer piece and the truss structure configuring a rigid body.